The iconic Adélie penguin is one of only two species to live and breed exclusively in Antarctica. This large population of penguins known for the Tuxedo pattern and their migrations of thousands of miles across the Antarctic, is surprisingly fragile.

Though the penguins spend most of the year living on sea ice, they need solid, dry, ground to breed, incubate their eggs, and raise their chicks.

Once the penguins have mated, and the eggs have been laid, the long incubation period, seen here, begins.

Researchers estimate that the population of Adélie penguins has declined by 65 percent over the past 25 years.

The main problem is the Antarctic’s melting sea ice.

Though the penguins breed on dry land, they need sea ice to hunt for food. And, though some models indicate that it is unlikely all of the ice in Antarctica will melt, the pace of glacier recession has accelerated in the last decade.

The chicks hatch in late December and in early January.

During the incubation and earliest juvenile stages, the parents work in shifts with one hunting for food while the other stays with the egg or chick. Often, the parent left at the nest endures long periods without eating at all.

Eventually, the parents need to leave to find food. They face numerous dangers including encounters with leopard seals.

The loss of ice contributes to the decline as well as diminished populations of Antarctic sea krill, the penguins main prey.

Nearby, a lone penguin wanders the grounds of an extinct colony on Torgersen Island. The sad scene is becoming increasingly common in the Antarctic, and penguins are not the only ones affected.